Abstract: A preliminary investigation which indicates the use of the forelimb data has limitations in accurately determining laterality in hoses

Forelimb observations are commonly used to determine motor laterality, however the hind limb in most cases initiates movement. Two preliminary studies were conducted to identify whether a relationship existed between fore and hind limb preference, and whether kinematic measurements of the trot characteristics were associated with the preferred forelimb. Statistical analysis was not possible due to small sample populations. Six horses (various breed/sex, mean age 10.3 ± 5.5 years) were left to navigate towards a feed bucket in an enclosed arena. Frequency data were collected from observations of the hind limb used to initiate movement, and forelimb advancement while eating. Laterality index scores were calculated. The right hind limb initiated movement during 57% of observations (hind limb laterality index = 13.33). The left forelimb was advanced while eating for 51% of observations (forelimb laterality index = -1.69). In the second study, four horses (two mares, two geldings, mean age 18 ± 2.8 years) were observed while eating a forage ration from the floor to establish forelimb preference. For kinematic analysis, skin markers indicated the centres of rotation for major joints of the appendicular skeleton. Horses were trotted in-hand three times in each direction past a Casio high speed video camera (10m from the plane of motion). Measurements of mobilising and stabilising limb traits were averaged for each direction. Individual asymmetries were noted but these were not associated with forelimb preference. Results from both studies indicate hind limb and forelimb preference are not associated; further study is required to better understand directional bias within equine training.